Fixes the issue multi-touch causing launcher icons to be not clickable.

The issue occurs because TextView#isFromPrimePointer assumes multi-touch
events are happening on the same TextView and relies on
ACTION_UP/ACTION_CANCEL to reset the Prime pointer id.

consider following scenario:
1. ACTION_DOWN (pointer 0) landed on ViewA,
   ACTION_DOWN (pointer 1) landed on ViewB.
2. ACTION_MOVE landed on both ViewA and ViewB, triggering a drag.
3. When all fingers are released, ACTION_CANCEL (pointer 0) will be
   landed on both ViewA and ViewB, so the prime pointer in ViewB is not
   reset due to pointer index mismatch.

This CL always reset prime pointer id whenever ACTION_UP/ACTION_CANCEL
is triggered.

Bug: 157399040
Test: manual
Change-Id: Id35d9eac939378482fa50e85bb5cda58469240ad